Firefighters were called to a two-storey house on Willowside Way at around 9.15pm to tackle the blaze, which neighbours have described as “horrendous” and “terrifying”.

No-one was inside the house at the time and crews from Royston, Buntingford, Letchworth and Baldock, and Stevenage took just over an hour to put the fire out.

A 52-year-old woman from Royston was arrested on suspicion of arson the following morning, questioned, and released on bail pending further inquiries. She will appear at Stevenage Police Station on September 1.

Neighbour Anne Howard, who lives in Willowside Way, said: “I was coming home from Tesco and I could smell smoke, which initially I thought was coming from a barbecue, but then I saw flames leaping out of the windows of the house as a I turned the corner.

“There was a lot of banging, the windows were exploding out and it looked really ferocious. It was terrifying because we didn’t know if anyone was in there, but the fire brigade told us it was empty. There were lots of fire engines around and the police stayed all night.”

A woman living in nearby Donne Close, who wished to remain anonymous, also witnessed the fire.

She said: “We were just watching television when my boys started screaming ‘fire’. I rushed outside and saw lots of lights flashing over the road. The whole house was engulfed in flames and smoke was billowing out of the windows.

“I haven’t seen a house fire before but it was one of the most intense things I’ve ever seen. It was going up in flames so quickly.”

Another resident living in Chaucer Road, who also asked not to be named, said: “It was awful. There was lots of black smoke coming out from the house and a horrendous smell of burning plastic. It was shocking to see, terrible, but thankfully no-one was inside.”